How reliable is Luis Munoz Marin International Airport?
Flights from SJU departed within 15 minutes of schedule in 77% of 196,056 flights in official BTS history — and weather is calmest in Mar. Here’s the full picture before you book.
Reliability score
on-time, cancellations & delays
Weather favorability
year-round climate
Origin-airport operations
What the departure punctuality at SJU looks like
On-time departures
across 196,056 flights
Source: BTS Airport Operations · data through 2026-06-25. Role-specific BTS departure history; advisory context, not a guarantee for any flight.
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Weather by month
When the weather works for you at San Juan
A calm-weather score (0–100) for each month from decades of airport observations — how often conditions disrupt flying, not temperature. Higher is calmer.
Calmest month
Calmest flying weather of the year · 99/100 favorability
Roughest month
Most disruptive — thunderstorms, low visibility & fog · 98/100 favorability
The read on SJU
What the numbers say about flying through Luis Munoz Marin International Airport
Across official performance history, flights from San Juan left within 15 minutes of schedule about 77% of the time over 196,056 flights. That's a respectable but unspectacular operational record. Pair it with a moderate cancellation rate of 1.7%. When a departure does run late, the typical delay is around 17 minutes.
On weather, San Juan is an unusually calm-weather airport year-round. March is the calmest stretch for flying, scoring 99 out of 100 for favorable conditions, while September is the most disruptive at 98, driven mainly by thunderstorms and low visibility & fog. The year is relatively steady, so no single month stands out as one to avoid on weather alone.
None of this guarantees your specific flight — it’s the backdrop. To turn it into a booking, score real flights to San Juan, read how we weigh it all in how the PlaneSane Score works, and brush up with how to pick a reliable flight and avoiding weather delays.
Common questions about SJU
- How reliable is Luis Munoz Marin International Airport (SJU)?
- Flights from San Juan left within 15 minutes of schedule roughly 77% of the time across 196,056 flights of official history — a respectable but unspectacular operational record. The cancellation rate runs about 1.7%. It's advisory context, not a guarantee for any single flight.
- What is the best month to fly from SJU for good weather?
- March has the calmest flying weather at Luis Munoz Marin International Airport. September is the most disruptive, mainly from thunderstorms and low visibility & fog.
Planning a trip through San Juan?
Score real flights to and from SJU on reliability, weather, and connection safety — not just price.